The present invention relates to a method and apparatus for the detection of deception.
Detection of deception has importance in many fields. There are obvious applications for detection of deception in law enforcement. Employment screening is another area in which there is need for a reliable means for detection of deception. Other areas in which detection of deception has utility include the screening of insurance or medical claims.
For example, claims of amnesia are frequently raised in a variety of legal situations. Amnesia may be easily feigned, and it is difficult, if not impossible to identify. Neuropsychologists have been used to attempt diagnosis and provide expert testimony in personal injury litigation cases involving such claims. A vital concern is their ability to distinguish between actual and exaggerated impairment. In many cases, their capability to detect feigned impairment is limited.
Tests have been devised to detect memory deficit malingering. The Hiscock Forced Choice Procedure (FCP) is such a test (See, Hiscock, M., & Hiscock, C. K. , Refining the forced-choice method for detection of malingering. Journal of Clinical and Fxperimental Neuropsychology, 11, 967-974 (1989)). This procedure is a simple delayed matching-to-sample task using multi-digit numbers. An increasingly long interval between sample and test numbers may make the test appear difficult, but in actuality, task difficulty is low and recognition of the first digit alone is sufficient for correct response. Normals and non-litigating patients with mild to moderate head injury perform at a rate of 100% correct, typically, on this relatively easy test.
It has been demonstrated that brain waves, in particular the P300 event-related potential (ERP), can be used successfully in detection of deception and malingering. This has been described in U.S. Pat. Nos. 4,932,416, 5,113,870, 5,137,027, and 5,622,181 (the disclosures of which are incorporated by reference herein) and in publications by Towle, V. T., Sutcliffe, & Sokol, S., Diagnosing functional visual deficits with the P300 component of the visual evoked potential, Archives of Opthalmology, 103, 47-50 (1985); Rosenfeld, J. P., Nasman, V. T., Whalen, R., Cantwell, B., & Mazzeri, J., Late vertex positivity in event-related potentials as a guilty knowledge indicator. A new method of lie detection. International Journal of Neuroscience, 34, 125-129 (1987); Rosenfeld, J. P., Cantwell, G., Nasman, V. T., Wojdac, V. Ivanov, S., & Mazzeri, L., A modified, event-related potential-based guilty knowledge test, International Journal of Neuroscience, 24, 157-161(1988); Rosenfeld, J. P., Angell, A., Johnson, M., & Qian, J., An ERP-based, control-question lie detector analog: Algorithms for discriminating effects within individuals' average waveforms. Psychophysiology, 38, 319-335 (1991); Rosenfeld, J. P., Sweet, J. J., Chuang, J., Ellwanger, J & Song, L., Detection of simulated malingering using forced choice recognition enhanced with event-related potential recording, The Clinical Neuropsychologist, 10, 163-179 (1996); Farwell, L. A., & Donchin, E., The truth will out: Interrogative polygraphy ("lie detection") with event-related potentials, Psychophysiology, 28, 531-547 (1991); Allen, J., Iacono, W. G. and Danielson, K. D., The identification of concealed memories using the event-related potential and implicit behavioral measures: A methodology for prediction in the face of individual differences, Psychophysiology, 29, 504-522 (1992); and Ellwanger, J., Rosenfeld, J. P. Sweet, J. J. & Bhatt, M., Detecting simulated amnesia for autobiographical and recently learned information using the P300 event-related potential, International Journal of Psychophysiology, 23, 9-23 (1996).
In these studies, the P300 component measured at the Pz locus has been the basic dependent variable analyzed. While such approaches have yielded up to about 90% accuracy in detecting guilt or innocence, there still remains a need to provide a means for detection of deception that is more reliable.